Pathfinder - How to Play 3 - Skills

Most tasks outside of combat are accomplished using skills. Skills represent a
creature's ability to accomplish a variety of tasks.

For descriptions of individual skills, check the
Skill Descriptions
page on the Pathfinder SRD.

Trained and Untrained Skills

A Trained skill is a skill in which the creature has at least one skill rank. This
indicates that the creature has taken some time to practice or learn the skill. Some
skills can be used untrained (Climb, Jump, Swim), but some skills require training to
be used (Knowledge) skills.

Class Skills

Class skills are determined by your character class. It is easier for your character
to become more proficient in these skills, as they represent part of his professional
training and constant practice. If you are trained in a class skill, you get a free +3
bonus to that skill. Because this is a nice bonus, it is often a good idea to put one
rank in several of your class skills, even if you don't think that you will need them
often. If you have more than one class and both grant you the same class skill, you
do not gain this bonus more than once.

Acquiring Skills

Each level, your character gains a number of skill ranks dependent upon your class
plus your Intelligence modifier. Investing a rank in a skill represents a measure of
training in that skill. You can never have more ranks in a skill than your total number
of Hit Dice.

For the number of skill ranks gained per level, see your class's description. If
you are human, you gain one bonus skill rank after calculating your normal number of
skill ranks per level.

Taking 10

When your character is not in immediate danger or distracted, you may choose to
take 10. Instead of rolling 1d20 for the skill check, calculate your result as if you
had rolled a 10. For many routine tasks, taking 10 makes them automatically successful.
Distractions or threats (such as combat) make it impossible for a character to take
10. Taking 10 is a good option if you are guaranteed to succeed on a 10, but failure
would have consequences. It also helps remove the need to roll dice repeatedly for
checks which you would rarely fail.

Taking 20

When you have plenty of time, you are faced with no threats or distractions, and
the skill being attempted carries no penalties for failure, you can take 20. In other
words, if you roll a d20 enough times, eventually you will get a 20. Instead of rolling
1d20 for the skill check, just calculate your result as if you had rolled a 20.

Taking 20 means you are trying until you get it right, and it assumes that you
fail many times before succeeding. Taking 20 takes 20 times as long as making a
single check would take (usually 2 minutes for a skill that takes 1 round or less to
perform).

Since taking 20 assumes that your character will fail many times before succeeding,
your character would automatically incur any penalties for failure before he or she
could complete the task (hence why it is generally not allowed with skills that carry
such penalties).

It is common for players to Take 20 when searching a room, or performing other
tedious tasks which would normally require a long time and a lot of rolling.

Aid Another

If you want to assist an ally with a skill check, you can Aid Another. To do so,
roll a skill check in the same skill against a DC of 10. If you succeed, you grant
your ally a +2 bonus to their check. If you and your ally both have the same skill,
it is often a good idea for the character with the highest skill modifier to make
the skill check while the other character assists. You can't assist with every skill
check, and which akills chacks allows assistance is up to your GM.